// 
// Copyright (c) 2006-2008 Ben Motmans
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
// Author(s):
//    Ben Motmans <ben.motmans@gmail.com>
//

using System;
using System.IO;

namespace Anculus.Core
{
	public class ArchivedFileLogBackend : FileLogBackend
	{
		protected int maxArchives;
		
		public ArchivedFileLogBackend (string filename)
			: this (filename, 1024, true, 3)
		{
		}
		
		public ArchivedFileLogBackend (string filename, int maxLogSize)
			: this (filename, maxLogSize, true, 3)
		{
		}
		
		public ArchivedFileLogBackend (string fileName, int maxLogSize, bool keepAlive, int maxArchives)
			: base (fileName, maxLogSize, false, keepAlive)
		{
			MaximumArchives = maxArchives;
		}

		public int MaximumArchives
		{
			get { return maxArchives; }
			set {
				if (value < 1)
					throw new ArgumentException ("MaximumArchives must be at least 1.");
				maxArchives = value;
			}
		}
		
		protected override void LogFull ()
		{
			//force close
			Close (true);
			
			string previousArchiveName = null;
			for (int i = maxArchives; i >= 0; i--) {
				string archiveName = String.Concat (FileName, ".", i);

				if (i == maxArchives) {
					//the last archive, must be deleted if it exists
					if (File.Exists (archiveName))
						File.Delete (archiveName);
				} else if (i == 0) {
					//the log file itself must be archived
					if (File.Exists (FileName))
						File.Move (FileName, previousArchiveName);
				} else {
					//the archive must be moved
					if (File.Exists (archiveName))
						File.Move (archiveName, previousArchiveName);
				}
				
				previousArchiveName = archiveName;
			}
		}
	}
}